1. Field of the Invention
The present invention is directed to a culture and transport assembly for a percutaneous access device which will enable the culturing of a fibroblast layer upon a selected portion of the access device and the shipping or transport of the access device without removal of the access device from the container in which it is sealed when manufactured.
2. Description of the Related Art
In U.S. Pat. No. 4,634,422 there is disclosed a percutaneous access device, a method for culturing a fibroblast layer upon a selected portion of that device, and a method for implanting the device in a human body. As described in that patent, a percutaneous access device is employed to establish a fluid or electrical connection through the skin of a patient from an external device to an organ or device implanted within the patient's body. The percutaneous access device must project through the patient's skin and the epidermis will attempt to close the opening through which the access device projects. This natural action of the epidermis can eventually marsupialize and tend to extrude the entire access device or, more typically, create sinus tracks which provide ideal conditions for the development of infection.
The foregoing problem was addressed by the subject matter of Patent 4,634,422 by utilizing apparatus and methods which enable a firm bond to be formed between the dermal layer of the patient's skin and the implanted access device which blocks downward growth of the epidermal layer along the sides of the device. As disclosed in that patent, the access device was constructed with a detectable sleeve which, when assembled on the device, formed that portion of the device which projected through the dermal layer when the device was implanted. In preparation for implantation, the sleeve was removed from the access device and a multi-layer coating of dermal cells was cultured on the external surface of the sleeve under laboratory conditions, by a procedure described in Patent 4,634,422. The sleeve, with the cultured dermal cell coating, was reassembled onto the access device immediately prior to implantation.
The technique described above presented the advantage of establishing a relatively small surface area onto which the cell layer was cultured by the employment of the removable sleeve. It also enabled the cell coating to be bonded to the sleeve under controlled, sterile laboratory conditions which enabled the coating to be firmly bonded to the sleeve prior to implantation. Attempting to bond the dermal cells directly to the sleeve while implanted in the patient was not feasible because of the unavoidable movement or stretching of the patient's skin made the formation of the bond difficult. Bonding of the dermal layer cultured on the sleeve to the dermis upon implantation required but a few days, while the bonding of the dermal layer to the sleeve would normally require two or more weeks under laboratory conditions.
While the foregoing technique represented a substantial improvement over the prior art, it also presented new problems. Culturing the dermal layer upon the sleeve was performed in a laboratory which was frequently remote from the medical facility in which the implantation was performed. This required not only transport of the sleeve with its cultured layer from the laboratory to the medical facility, but also required extremely careful handling in the assembly of the sleeve upon the device just prior to implantation. At this stage, the dermal layer cultured on the exterior of the sleeve was quite thin and fragile.
The present invention is directed to a solution of these last problems.